brijncker



(No Model.) 2 Sheets-Shet 1.

E. BRUNGKER.

SEWING MACHINE.

Patented Dec. 27,1881.

n. PETERS. Phnlo'Lilhognpher. Walhingtnn. n. c,

(No Model.) 2 Sheets-Sheet 2.

E. BRUNOKER.

SEWING MACHINE.

Patented Dec. 27,1881.

iii/Vania?! W UNITED STATES PATENT OEEIcE.

EWALD BRUNGKER, OF KOLN-ON-THE-RHINE, PRUSSIA, GERMANY.

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 251,517, dated December 27, 1881,

Application filed July 13, 1881. (No model.) Patented in Germany August 23, 1880.

To all whom at may concern:

Be it known that I, EWALD BRUNOKER, residing in Koln-on-the-Rhiue, Kingdom of Prussia, Germany, have invented a new and useful Lock-Stitch Sewing-Machine, (for which a patent has been applied for only in Germany on the 23d August, 1880,) of which the following is a specification.

This invention relates to double-lock-stitch sewing-machines-i. e., to machines in which the upper and the lower thread are interlaced by causing the, spool containingthe lower thread to pass through the loop of the upper thread; and the improvements consist, first,

in placing the lower spool into a round shuttle, to which a continuous rotative motion is imparted, whereas the spool does not rotate; and, secondly, in providing for the upper thread a new kind of a tension device.

The invention is represented on the annexed two sheets of drawings.

Figure l is a top view, and Fig. 2 a side view, of the rotating shuttle; Fig. 3, section of shuttle on line 2 z of 1,-with mechanism for propelling the same faster at a certain point of its rotation; Fig. 4, tension device for the spool of the lower thread in plan and elevation; Fig. 5, the spool in section; Fig. 6, section showing the shuttle bedor hearing and the shuttle, in which is inserted the spool, together with the tension device; Fig. 7, top View of shuttle and bed, with parts appertaining thereto; Fig. 8, view of shuttle-driver; Fig. 9, side View of shuttle-bed, 820.; Fig. 10, rear view, and Fig. 11 side view, of the shuttle and its driver in working position. In Fig. 11 the shuttle-bed and frame for the driveraxle are also shown Figs. 12, 13, and 14, modified forms of rotating shuttle; Fig. 15, front end view of the machine; Fig. 16, front side elevation of the same; Fig. 17, section of tension device for the upper thread; Fig. 18, modification of the shuttle-driver.

The spool 0, Fig. 5, is placed on the central tubular part, i, of the tension device'B, Fig. 4:, through the slits and holes of which the thread f is passed for causing the necessary tension. This device B fits, with its said tubular part i, tightly on the bush d, Fig. 3, revolving on a pin, 0, fixed in the center of the shuttle A. The bush dis prevented from slipping ofi the pin 0 by the knob e, which is somewhat smaller in diameter than (1, so that the shuttle A may freely rotate, while the partB and the spool O are held stationary by the thread f. The spool, of course, turns within the part B by the winding off of the thread during the operation of sewing. If it should be preferred, the spool and its tension might be placed loose into the shuttle.

The shuttle, which in its outward shape resembles two truncated cones united with their base, rotates in a bearing, D, by preference composed of two plates, 70 and I, Fig. 6, provided at q with a slit for the needle and the loop to pass through. This figure also shows the spool and the tension device introduced into the shuttle. The outer form of the shuttle may, however, be modified, asis represented in Figs. 12, 13, and 14. Moreover, the bearing D may be formed of a series of anti-friction rollers of suitable shape. The shuttle is recessed on a part of its circumference in the manner shown by Figs. 1 and 2, and so that on the left-hand side (with regard to these figures) a hook, 0, and on the opposite side a shoulder, 0 are formed, the object of the hook being to catch the loop of the upper thread, whereas the shouldeuo? is the point against which the driver '1 Fig. 8, acts by its edge 70 This driver consists of a disk fixed on a shaft, 0, Fig. 11, rotating in bearings b and b, and provided with a projecting part, k P, forming a skew surface. The said part 70 l fits in such a inanner'into the recessed part of the shuttle that the edge l (which is vertical to the disk of the driver) will lie in the throat of the hook 0, whereas the edge 70 is in contact with the shoulder 0 as already stated. (See also Figs. 7 and 10.) V

The bed D of the'shuttle is, by preference, fitted in an inclined position to the bed-plate of the machine, as shown by Figs. 11 and 15, and so thatthe needle will pass through the slit q of the bed and along the lower conical side of the shuttle; but the shuttle may also be arranged in a vertical ora horizontal position, if desired. When placed horizontally the needle should, however, make a stop during its upward motion, so as to allow the shuttle to pass freely through the loop.

The driver is rotated by the bevel-wheels and g Figs. 3, 11, 15, and 16, the wheel 1 being keyed on the main shaft 20. Between the shuttle and the driver there is sufficient play for allowing the upper thread to pass, except the point where the driver, by its edge bears against the shoulder 0 of the shuttle. An arrangement is therefore required which acts instead of the driver 3 at the moment the thread has to pass between R and 0 and which separates these points from each otherduring such passage. The mechanism serving for this purpose is represented in Fig. 3. It consists of a finger, h, attached to the shaft to, andso timed with regard to the rotation of the shuttle that it will at every rotation enter into the recess a of the shuttle. The radius of the finger h being, moreover, somewhat larger than the radius drawn from the axis of A to the recess M, the said finger will during its action accelerate the rotative speed of A by so much as to cause the required separation of the points 0 and k As soon as h leaves the recess a the driver y again resumes its operation. Ifpreferred, the speed of the end of the finger h and the recess a may be equal; but in this case the arrangement must be so madethat h upon entering inton will cause the shuttle to be ad vanced by as much as is required for causing the necessary play between k and 0 The loop of the upper thread, when passing the shuttle, is operated upon, in the manner to be described hereinafter, by a tongue, 4, Figs. 7, 9, 10, and 11, and by a projection, e, on the lower face of the shuttle. The tongue 1' is jointed ats to the shuttle-bed D, and a spring, L, serves to keep it in its place, while it may be turned aside by the knob i when the spool is to be exchanged. The point of the tongue reaches to the center of the shuttle and just leaves sufficient room between it and the tension B for the passage of the thread.

A modification of the driver is shown by Fig. 18. It consists in this case of a disk, with three or more driving pins, and it is placed at a certain angle to the shuttle, so that at least one of the driving-pins will always be out of engagement to let the loop pass around the shuttle. I

Figs. 15 and 16 show the general arrangement of the improved machine. The needlebar is worked from the shaft 11, by an eccentric, eccentric-rod a, rockin g-shaft w and rockerarm 2, coupled by a connecting-link to the bar a; but any other known and suitable arrangement may be applied for this purpose.

For imparting to the upper thread the requisite tension, and for allowing this tension to be regulated with facility, the device k, Fig. 16, and shown in Fig. 17 in section, may be used. It consists of two disks or plates secured together by the screws 02 and 0, and between which the clamping-plates r and s and a springing-plate, q, are placed. The said plates 1 and s are bent so as to allow of being brought in contact with each other at the middle, and they may be pressed together (more or less) by the screw q. The thread is drawn, in the manner shown by Fig. 16, over the screw-bolts n and 0 or the washers with which these are provided. It will thereby pass between the plates r and s, where its friction can be increased or diminished by turning the screw p.

The operation of the machine is as follows: The motions of the needle and of the shuttle are so timed with respect to each other that the hook 0 of the shuttle will be close to the needle when the latter, after having descended, begins to rise. The hook consequently enters into the loop formed by the needle and enlarges the same, and when the loop has slipped into the throat of the hook it will be drawn over the shuttle. The under part of the loop passes into the space between the driver and the bottom surface of the shuttle, and here meets the projection 0, which causes a further extension of the loop. (See Fig. 10.) The throat of the book 0 having arrived at its lowest point, the upper part of the loop slips on the tongue 0, as is also shown in Fig. 10. The loop is now stretched to its greatest extent, so that the further motion of the shuttle causes it to become slack. This slack is still increased on account of the leading edge of the projection e (which tapers out into the bottom of the shuttle) passing at this period under the lower loop part and allowing it to slip off. A part of the slack thus produced is taken up by the needle which is descending again, whereas a part is retained by the tongue 1" in the manner shown by Fig. 7. Meanwhile the finger h has accelerated the motion of the shuttle, or thrown it forward by so much as to cause it to become free of the propelling edge of the driver, in consequence whereof the needle, proceeding in its'descent, draws the under part of the loop through the space thus produced. The entire loop, which has now encircled the under thread, is thereby brought to the top of the shuttle, and is there retained by the tongue 1; but it is not taken up any farther by the needle, which has finished its downstroke. The second rotation of the shuttle now begins. Its hook 0 again enters into the loop of the needle, but the tension apparatus of the upper thread presenting resistance, the shuttle first of all pulls the spare thread@'. 0., the remaining portion of the first loop-0E the ton giie r and locks the stitch, as represented in Fig. 11. The following stitches are form ed by a repetition of the same process.

If it should be preferred, the stitch may be completed at the end of every single rotation of the shuttle by means of a take-up provided for this purpose.

I claim as my invention- 1. The rotating shuttle A, containing the under-thread spool 0, together with a suitable tension device, and provided with a hook, 0, in combination with a bed or bearing, D, the driver '2 and the rotating accelerating-finger h, substantially as and for the purposes hereinbefore set forth.

2. The combination, with the rotating shutconsisting of the clamping-plates r and 8, tie and the shuttle bed or bearing, of pivoted screw-bolts n and o, springing-plate q, and tongue 7', constructed and arranged with relaadjusting-screw p, as and for the purpose de- 15 tion to the shuttle as described, and the tonguescribed.

5. controlling spring 1, bearing against base or In testimony whereof I have signed my name 7 butt of the tongue, substantially as and for to this specification in the presence of two subthe purposes set forth. scribing witnesses.

3. The rotating shuttle A, provided with projection e, in combination with a bed or 10 bearing D, and tongue 1', substantially as Witnesses:

hereinbefore specified. HEINRICH SPRINGMANN,

4. The tension device for the upper thread, CARL WEINGMANN.

EWVALD BRUNOKER. 

